Insulin resistance as a determinant of platelet activation in obese women

OBJECTIVES We tested the hypothesis that insulin resistance, per se, contributes to increased platelet activation in obesity, independently of underlying inflammation. BACKGROUND Obesity, insulin resistance, and atherosclerosis are closely linked phenomena associated with low-grade inflammation. Obesity is associated with persistent platelet activation in otherwise healthy women. METHODS We performed a cross-sectional study in 40 obese and 20 non-obese healthy women using urinary thromboxane metabolite excretion as a non-invasive index of platelet activation. An index of insulin sensitivity, S, and plasma adiponectin, C-reactive protein (CRP), and CD40 ligand (CD40L) levels were measured. RESULTS Obese women had significantly (p < 0.0001) higher 11-dehydro-thromboxane B-2 (11-dehydro-TXB2) excretion (median 718 vs. 211 pg/mg creatinine), CRP (1.13 vs. 0.48 mg/1), and CD40L levels (4.45 vs. 0.90 ng/ml) than controls. Obese women had lower S, (median 2.51 vs. 5.0 10(4) min(-1)/[mu U/ml], p < 0.002) and adiponectin (6.3 vs. 10 mu g/ml, p < 0.01) than control subjects. On multiple regression analysis, waist-to-hip ratio (beta = 0.27, p < 0.05) and S, (beta = -0.72, p < 0.04) predicted 11-dehydro-TXB2 excretion rate, independently of adiponectin, CRP, CD40L, and lipid patterns. In order to investigate the cause-effect relationship of these associations, we examined the effects of a 12-week weight loss program or a 3-week pioglitazone treatment on urinary 11-dehydro-TXB2 in 10 women with impaired S-1 and visceral obesity. Successful weight loss (0.6 kg loss/week) achieved in 5 subjects was associated with increased S-1 (+92%) and decreased CD40L (-27%), CRP (-37%), and 11-dehydro-TXB2 (-53%) (p < 0.05). Consistently, improvement of insulin sensitivity achieved with pioglitazone significantly decreased urinary 11-dehydro-TXB2 excretion (-43%, p < 0.05) without changes in body weight. CONCLUSIONS Insulin resistance is a major determinant of platelet activation in female obesity

Mature PMN-MDSCs from G-CSF-treated healthy donors and cancer patients share a suppressive gene signature and CD84 expression

Recently, we demonstrated that neutrophil populations displaying polymorphonuclear myeloid derived suppressor cell (PMN-MDSC)-like features appear in abundance in both CD66b+ low-density neutrophils (LDNs) and normal-density neutrophils (NDNs) of healthy subjects receiving G-CSF for stem cell mobilization (GDs). We also uncovered that the mature, but not immature, fraction of PMN-MDSC populations present in GDs, similarly to what also shown by others in cancer patients, are those exerting the most potent immunosuppressive functions. Herein, by RNA-seq computational analysis, we report the identification and characterization of a distinct gene signature common to mature CD66b+CD11b+CD16+CD10+ LDNs/mNDNs from GDs (GD-mNDNs/mLDNs) and mature CD66b+CD11b+CD16+CD10+ PMN-MDSCs (mPMN-MDSCs) from head and neck (HNC) and non-small cell lung (NSCLC) cancer patients. We also show that this GD/NSCLC/HNC mPMN-MDSC gene signature derives, mostly from the maintenance of genes already expressed by normal immature neutrophil precursors, and in a minor, but more specific, quote, from genes selectively upregulated along the maturation of PMN-MDSC-committed cells. Furthermore, by searching for mRNAs included within the latter group of genes encoding surface proteins, we found CD84 expression markedly elevated on mPMN-MDSC populations, not only from GDs and HNC/NSCLC, but also from diffuse large B cell lymphoma (DLBCL), renal cell cancer (RCC), transitional cell carcinoma (TCC) and breast cancer (BC) patients. Overall, data prove that mLDNs and mNDNs from GDs represent excellent cellular models suitable either to define the molecular features, or to identify specific markers, that can be shared by mPMN-MDSC populations from different origin

Effects of Magnetic Nanoparticles on the Functional Activity of Human Monocytes and Dendritic Cells

The use of nanoparticles in medicine is sometimes hampered by their potential to activate immune cells, eliciting inflammation or allergy. We investigated whether magnetic nanoparticles (MNPs) or biomimetic magnetic nanoparticles (BMNPs) affect relevant activities of human monocytes. We found that the nanoparticles neither elicited the production of pro-inflammatory mediators IL-6 and TNFα by resting monocytes (when BMNP dose < 300 μg/mL) nor enhanced their secretion induced by R848, a molecule engaging virus-recognizing receptors, or bacterial lipopolysaccharide (LPS). MNPs and BMNPs neither induced the generation of reactive oxygen species (ROS), nor affected the ROS production elicited by the NADPH oxidase activator phorbol myristate acetate (PMA) or the fungal derivative β-glucan. BMNPs, but not MNPs, caused an up-regulation of the maturation markers CD80, CD83, and CD86 in immature monocyte-derived dendritic cells (DCs), whereas both nanoparticles did not affect the LPS-induced expression of these markers. Moreover, the nanoparticles were greedily ingested by monocytes and DCs without altering their viability. Therefore, these nanoparticles are candidates for medical applications because they do not activate pro-inflammatory activities of monocytes. Furthermore, their ability to stimulate DC maturation could be used for the design of vaccines. Moreover, harmlessly engulfed nanoparticles could be vehicles to carry molecules inside the immune cells to regulate the immune response

Neutrophils inhibit γδ T cell functions in the imiquimod-induced mouse model of psoriasis

Psoriasis is a chronic skin disease associated with deregulated interplays between immune cells and keratinocytes. Neutrophil accumulation in the skin is a histological feature that characterizes psoriasis. However, the role of neutrophils in psoriasis onset and development remains poorly understood

Polymerase ε (POLE) ultra-mutation in uterine tumors correlates with T lymphocyte infiltration and increased resistance to platinum-based chemotherapy in vitro

OBJECTIVE: Up to 12 % of all endometrial-carcinomas (EC) harbor DNA-polymerase-ε-(POLE) mutations. It is currently unknown whether the favorable prognosis of POLE-mutated EC is derived from their low metastatic capability, extraordinary number of somatic mutations thus imparting immunogenicity, or a high sensitivity to chemotherapy. METHODS: Polymerase-chain-reaction-amplification and Sanger-sequencing were used to test for POLE exonuclease-domain-mutations (exons 9–14) 131 EC. Infiltration of CD4+ and CD8+ T-lymphocytes (TIL) and PD-1-expression in POLE-mutated vs POLE wild-type EC was studied by immunohistochemistry (IHC) and the correlations between survival and molecular features were investigated. Finally, primary POLE-mutated and POLE-wild-type EC cell lines were established and compared in-vitro for their sensitivity to chemotherapy. RESULTS: Eleven POLE-mutated EC (8.5%) were identified. POLE-mutated tumors were associated with improved progression-free-survival (P<0.05) and displayed increased numbers of CD4+ (44.5 vs 21.8; P = .001) and CD8+ (32.8 vs 13.5; P < .001) TILs when compared to wild-type POLE EC. PD-1 receptor was overexpressed in TILs from POLE-mutated vs wild-type-tumors (81% vs 28%; P < .001). Primary POLE tumor cell lines were significantly more resistant to platinum-chemotherapy in-vitro when compared to POLE-wild-type tumors (P < 0.004). CONCLUSIONS: POLE ultra-mutated EC are heavily infiltrated with CD4+/CD8+ TIL, overexpress PD-1 immune-check-point (i.e., features consistent with chronic antigen-exposure), and have a better prognosis when compared to other molecular subtypes of EC patients. POLE-mutated tumor-cell lines are resistant to platinum-chemotherapy in-vitro suggesting that the better prognosis of POLE-patients is not secondary to a higher sensitivity to chemotherapy but likely linked to enhanced immunogenicity

Plasmacytoid Dendritic Cell, Slan+-Monocyte and Natural Killer Cell Counts Function as Blood Cell-Based Biomarkers for Predicting Responses to Immune Checkpoint Inhibitor Monotherapy in Non-Small Cell Lung Cancer Patients

: The advent of immune checkpoint inhibitors (ICIs), for instance, programmed cell death 1 (PD-1)/PD-1 ligand 1 (PD-L1) blockers, has greatly improved the outcome of patients affected by non-small cell lung cancer (NSCLC). However, most NSCLC patients either do not respond to ICI monotherapy or develop resistance to it after an initial response. Therefore, the identification of biomarkers for predicting the response of patients to ICI monotherapy represents an urgent issue. Great efforts are currently dedicated toward identifying blood-based biomarkers to predict responses to ICI monotherapy. In this study, more commonly utilized blood-based biomarkers, such as the neutrophil-to-lymphocyte ratio (NLR) and the lung immune prognostic index (LIPI) score, as well as the frequency/number and activation status of various types of circulating innate immune cell populations, were evaluated in NSCLC patients at baseline before therapy initiation. The data indicated that, among all the parameters tested, low plasmacytoid dendritic cell (pDC), slan+-monocyte and natural killer cell counts, as well as a high LIPI score and elevated PD-L1 expression levels on type 1 conventional DCs (cDC1s), were independently correlated with a negative response to ICI therapy in NSCLC patients. The results from this study suggest that the evaluation of innate immune cell numbers and phenotypes may provide novel and promising predictive biomarkers for ICI monotherapy in NSCLC patients

Inhibition of BET Bromodomain Proteins with GS-5829 and GS-626510 in Uterine Serous Carcinoma, a Biologically Aggressive Variant of Endometrial Cancer

Uterine serous carcinoma (USC) is a rare and aggressive variant of endometrial cancer. Whole-exome sequencing (WES) studies have recently reported c-Myc gene amplification in a large number of USCs, suggesting c-Myc as a potential therapeutic target. We investigated the activity of novel BET bromodomain inhibitors (GS-5829 and GS-626510, Gilead Sciences Inc.) and JQ1 against primary USC cultures and USC xenografts. We evaluated c-Myc expression by qRT-PCR in a total of 45 USCs including fresh-frozen tumor tissues and primary USC cell lines. We also performed IHC and Western blot experiments in 8 USC tumors. USC cultures were evaluated for sensitivity to GS-5829, GS-626510, and JQ1 using proliferation, viability, and apoptosis assays. Finally, the activity of GS-5829, GS-626510, and JQ1 was studied in USC-ARK1 and USC-ARK2 mouse xenografts. Fresh-frozen USC and primary USC cell lines overexpressed c-Myc when compared with normal tissues ( = 0.0009 and 0.0083, respectively). High c-Myc expression was found in 7 of 8 of primary USC cell lines tested by qRT-PCR and 5 of 8 tested by IHC. experiments demonstrated high sensitivity of USC cell lines to the exposure to GS-5829, GS-626510, and JQ1 with BET inhibitors causing a dose-dependent decrease in the phosphorylated levels of c-Myc and a dose-dependent increase in caspase activation (apoptosis). In comparative experiments, GS-5829 and/or GS-626510 were found more effective than JQ1 at the concentrations/doses used in decreasing tumor growth in both USC-ARK1 and USC-ARK2 mouse xenograft models. GS-5829 and GS-626510 may represent novel, highly effective therapeutics agents against recurrent/chemotherapy-resistant USC-overexpressing c-Myc. Clinical studies with GS-5829 in patients with USC harboring chemotherapy-resistant disease are warranted.

Platelet cyclooxygenase inhibition by low-dose aspirin is not reflected consistently by platelet function assays: implications for aspirin "resistance"

This study was conducted to assess the thromboxane (TX) dependence of biochemical and functional indexes used to monitor the effect of low-dose aspirin